UPDATED: Teva, OncoGenex amp up Phase III fight against prostate cancer

As the field of contenders advancing new drugs for prostate cancer gets crowded, OncoGenex Pharmaceuticals ($OGXI) and partner Teva Pharmaceutical ($TEVA) are putting additional muscle behind their late-stage horse in the race, a compound called custirsen.

OncoGenex revealed the revamped custirsen strategy Thursday afternoon, saying the Bothell, WA, company and Teva plan to start a new Phase III trial for the drug in combination with Sanofi's ($SNY) chemotherapy drug Jevtana with the goal of improving survival of prostate cancer patients. The companies are nixing a trial called Saturn that was intended to test custirsen with reduction in cancer-related pain as the main endpoint. Meanwhile, the developers are boosting enrollment from 800 patients to 1,000 patients in a separate Phase III trial called Synergy, which aims to test custirsen in combination with chemo in patients with castration-resistant prostate cancer.

Prostate cancer--which is the second-most common cancer among U.S. men and is projected to cause 28,170 deaths in the country this year--has garnered lots of interest among biopharma companies. OncoGenex's retooled trial plan comes on the heels of Johnson & Johnson's ($JNJ) announcement of early success in a trial with the drug Zytiga in prostate cancer patients who had not yet been treated with chemo, a development that could greatly expand the market for the drug. And Medivation ($MDVN) and Exelixis ($EXEL) are in the hunt with drugs to serve segments of the prostate cancer market.

"I think there's going to be a really important need for an agent like custirsen to improve on chemotherapy as the other agents migrate to the pre-chemotherapy setting," OncoGenex CEO Scott Cormack said Thursday on a conference call, as quoted by Xconomy.

As Xconomy reports, OncoGenex expects to shell out more cash this year to bankroll the updated trial plan for custirsen, essentially doubling down on its original bet on the program to see that it has its best shot at FDA approval.

- here's the release
- get more in Xconomy's article

Editor's Note: Updated to clarify the type of prostate cancer that will be treated in the companies' "Synergy" trial.